The Society of Thoracic Surgeons 2008 Cardiac Surgery Risk Models: Part 2-Isolated Valve Surgery

Duke Clinical Research Institute, Durham, North Carolina, USA.
The Annals of thoracic surgery (Impact Factor: 3.85). 07/2009; 88(1 Suppl):S23-42. DOI: 10.1016/j.athoracsur.2009.05.056
Source: PubMed


Adjustment for case-mix is essential when using observational data to compare surgical techniques or providers. That is most often accomplished through the use of risk models that account for preoperative patient factors that may impact outcomes. The Society of Thoracic Surgeons (STS) uses such risk models to create risk-adjusted performance reports for participants in the STS National Adult Cardiac Surgery Database (NCD). Although risk models were initially developed for coronary artery bypass surgery, similar models have now been developed for use with heart valve surgery, particularly as the proportion of such procedures has increased. The last published STS model for isolated valve surgery was based on data from 1994 to 1997 and did not include patients undergoing mitral valve repair. STS has developed new valve surgery models using contemporary data that include both valve repair as well as replacement. Expanding upon existing valve models, the new STS models include several nonfatal complications in addition to mortality.
Using STS data from 2002 to 2006, isolated valve surgery risk models were developed for operative mortality, permanent stroke, renal failure, prolonged ventilation (> 24 hours), deep sternal wound infection, reoperation for any reason, a major morbidity or mortality composite endpoint, prolonged postoperative length of stay, and short postoperative length of stay. The study population consisted of adult patients who underwent one of three types of valve surgery: isolated aortic valve replacement (n = 67,292), isolated mitral valve replacement (n = 21,229), or isolated mitral valve repair (n = 21,238). The population was divided into a 60% development sample and a 40% validation sample. After an initial empirical investigation, the three surgery groups were combined into a single logistic regression model with numerous interactions to allow the covariate effects to differ across these groups. Variables were selected based on a combination of automated stepwise selection and expert panel review.
Unadjusted operative mortality (in-hospital regardless of timing, and 30-day regardless of venue) for all isolated valve procedures was 3.4%, and unadjusted in-hospital morbidity rates ranged from 0.3% for deep sternal wound infection to 11.8% for prolonged ventilation. The number of predictors in each model ranged from 10 covariates in the sternal infection model to 24 covariates in the composite mortality plus morbidity model. Discrimination as measured by the c-index ranged from 0.639 for reoperation to 0.799 for mortality. When patients in the validation sample were grouped into 10 categories based on deciles of predicted risk, the average absolute difference between observed versus predicted events within these groups ranged from 0.06% for deep sternal wound infection to 1.06% for prolonged postoperative stay.
The new STS risk models for valve surgery include mitral valve repair as well as multiple endpoints other than mortality. Model coefficients are provided and an online risk calculator is publicly available from The Society of Thoracic Surgeons website.

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    • "The surgical risk and possible postoperative complications of the patients were defined by calculating the STS10 score and logistic EuroSCORE11. "
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    ABSTRACT: Background: Transcatheter aortic valve implantation is an effective alternative to surgical treatment of severe aortic stenosis in patients who are inoperable or at high surgical risk. Objectives: To report the immediate and follow-up clinical and echocardiographic results of the initial experience of transcatheter aortic valve implantation. Methods: From 2009 June to 2013 February, 112 patients underwent transcatheter aortic valve implantation. Results: Mean age was 82.5 ± 6.5 years, and the logistic EuroSCORE was 23.6 ± 13.5. Procedural success was 84%. After the intervention, a reduction in the mean systolic gradient was observed (pre: 54.7 ± 15.3 vs. post: 11.7 ± 4.0 mmHg; p < 0.01). Cerebrovascular accidents occurred in 3.6%, vascular complications in 19% and permanent pacemaker was required by 13% of the patients. Thirty-day mortality and at follow-up of 16 ± 11 months was 14% and 8.9% respectively. The presence of chronic obstructive pulmonary disease was the only predictor of mortality at 30 days and at follow-up. During follow up, aortic valve area and mean systolic gradient did not change significantly. Conclusions: Transcatheter aortic valve implantation is an effective and safe procedure for the treatment of aortic stenosis in high-surgical risk or inoperable patients. The presence of chronic obstructive pulmonary disease was the only independent predictor of mortality identified both in the first month post-intervention and at follow-up.
    Full-text · Article · Apr 2014 · Arquivos Brasileiros de Cardiologia
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    • "Strokes/TIAs (as defined in Table 1) are more common post-TAVI than after alternative management strategies, with the highest reported incidence for any cardiac procedure [2]. Thirty-day stroke rates of 3.3%, 2.4% and 1–2% have been reported for populations undergoing TAVI, isolated SAVR, and balloon valvuloplasty, respectively [3-5]. For all three interventions, this risk is highest within the first 24 hours, suggesting an early hazard phase immediately post-procedure [6,7]. "
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    ABSTRACT: The incidence of clinically apparent stroke in transcatheter aortic valve implantation (TAVI) exceeds that of any other procedure performed by interventional cardiologists and, in the index admission, occurs more than twice as frequently with TAVI than with surgical aortic valve replacement (SAVR). However, this represents only a small component of the vast burden of neurological injury that occurs during TAVI, with recent evidence suggesting that many strokes are clinically silent or only subtly apparent. Additionally, insult may manifest as slight neurocognitive dysfunction rather than overt neurological deficits. Characterisation of the incidence and underlying aetiology of these neurological events may lead to identification of currently unrecognised neuroprotective strategies. The Silent and Apparent Neurological Injury in TAVI (SANITY) Study is a prospective, multicentre, observational study comparing the incidence of neurological injury after TAVI versus SAVR. It introduces an intensive, standardised, formal neurologic and neurocognitive disease assessment for all aortic valve recipients, regardless of intervention (SAVR, TAVI), valve-type (bioprosthetic, Edwards SAPIEN-XT) or access route (sternotomy, transfemoral, transapical or transaortic). Comprehensive monitoring of neurological insult will also be recorded to more fully define and compare the neurological burden of the procedures and identify targets for harm minimisation strategies. The SANITY study undertakes the most rigorous assessment of neurological injury reported in the literature to date. It attempts to accurately characterise the insult and sustained injury associated with both TAVI and SAVR in an attempt to advance understanding of this complication and associations thus allowing for improved patient selection and procedural modification.
    Full-text · Article · Apr 2014 · BMC Cardiovascular Disorders
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    • "Aortic stenosis (AS) is a progressive disease with a poor prognosis if treated medically after symptom onset.1-4 Although surgical aortic valve replacement (SAVR) has been shown to improve symptoms and survival,5-7 patients with advanced age are at increased risk of surgical complications or death.8-10 With aging of the population, the number of very old patients with symptomatic severe AS has increased, and a significant portion of them are not candidates for SAVR because of advanced age and its associated comorbidities.11 "
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    ABSTRACT: Purpose Transcatheter aortic valve implantation (TAVI) has become an attractive therapeutic strategy for severe aortic stenosis (AS) in elderly patients due to its minimally-invasive nature. Therefore, early results of its clinical outcomes in elderly Korean patients were evaluated. Materials and Methods We compared early clinical outcomes of TAVI, surgical aortic valve replacement (SAVR), and optimal medical therapy (OMT) in patients aged ≥80 years with symptomatic severe AS. Treatment groups were allocated as follows: TAVI (n=10), SAVR (n=14), and OMT (n=42). Results Baseline clinical characteristics including predicted operative mortality were similar among the three groups. However, patients with New York Heart Association functional class III or IV symptoms and smaller aortic valve area were treated with TAVI or SAVR rather than OMT. In-hospital combined safety endpoints (all-cause mortality, major stroke, peri-procedural myocardial infarction, life-threatening bleeding, major vascular complication, and acute kidney injury) after TAVI or SAVR were significantly lower in the TAVI group than in the SAVR group (10.0% vs. 71.4%, respectively, p=0.005), along with an acceptable rate of symptom improvement and device success. During the follow-up period, the TAVI group showed the lowest rate of 3-month major adverse cardiovascular and cerebrovascular events, a composite of all-cause mortality, myocardial infarction, major stroke, and re-hospitalization (TAVI 0.0% vs. SAVR 50.0% vs. OMT 42.9%, p=0.017). Conclusion Treatment with TAVI was associated with lower event rates compared to SAVR or OMT. Therefore, TAVI may be considered as the first therapeutic strategy in selected patients aged ≥80 years with symptomatic severe AS.
    Full-text · Article · May 2013 · Yonsei medical journal
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